An example of electronic transactions using contactless cards relates to transport entitlements. These cards allow users to access means of transport by passing the former across readers placed at the entry points of stations or on entry to vehicles. The entitlements are realized and stored in the memory of the cards. Just as for conventional means, of the type for example of the orange cards in the Paris region, the entitlements stored in the cards correspond to various types of subscription or contracts as a function notably of the geographical area covered, the capacity of the user and the duration. Checking the validity of a subscription requires particular means contrary to a conventional paper entitlement where the characteristics of the subscription are visible. Notably, electronic reading means making it possible to read the content of the contract stored in a card are required. The agents in charge of checking transport entitlements must therefore be permanently equipped with apparatus for reading electronic supports such as memory cards for example.
These agents, the inspectors, must also have the capability of issuing transport entitlements or of modifying the contracts, for example the subscriptions. Their apparatuses must therefore also be capable of reading and writing the data registered in the memory of the cards.
These reading and writing apparatuses can also be used in fixed points of sale for example at newsagents that are authorized to issue transport entitlements. In particular the users must be able to reload their cards in these fixed points of sale.
The problem of security arises in regard to agents or points of sale, at newsagents for example. It is necessary in particular to prevent the utilization of electronic transactions in the event of theft of these reading and writing terminals which are generally of roaming type, be they carried by agents or installed in points of sale.